Automatic slide projector



Apfrl 2l, 1936. F. BRUNISH AUTOMATIC SLIDE PROJECTOR Filed May 2l, 19342 Sheets-Sheet l IN VEN TOR. i

pii 2L 11936.., 'FI BRUNlSH SFQ v AUTOMATIC SLIDE PROJECTOR Filed May2l,A 1934 2 sheets-sneer 2 'y' Hl INVENTOR. 'gl O' 2 /25 25X ff www u/Z8 5534 f 3451 Patented Apr. 21, 1936 UNITED STATES PATENT OFFICEAUTOMATIC SLIDE PROJECTOR geles, Calif.

Application May 21, 1934, Serial No. 726,657

9 Claims.

This invention relates to an automatic slide projector more particularlyintended to be used for advertising purposes, but not necessarilyrestricted to such a use.

The invention further pertains to that type of projection machineswherein a series of slides, usually l2 to 48 in number, are arranged tobe vautomatically displayed continuously at denite intervals of a fewseconds between each slide, the matter inscribed on a given set ofslides being thus repeatedly displayed until new slides are substituted.

An object of the invention is to provide a machine of the aforementionedkind that can be operated in a smaller space for a given size of screenor display iield than is possibleA in the case of machines of this kindwhich have hitherto been -in use. This object is attained by the use ofa novel arrangement of reflectors which provides room for expanding theimage the required amount without the necessity of building the machineon nearly so large a scale as would otherwise be necessary.

Other objects, advantages and features of invention may hereinafterappear.

Referring to the accompanying drawings, which illustrate what is atpresent deemed to be a preferred embodiment of the invention,

Fig. 1 is a perspective view of the machine, parts thereof being brokenaway in order to disclose structures that would otherwise be concealed.

Fig. 2 is a View of the dark chamber structure wherein certain externalparts are shown in transverse section; and the remaining parts are shownin plan.

Fig. 3 shows the dark chamber and parts therein in vertical mid-sectionexcept that some of the enclosed parts are shown in elevation.

Fig. 4 is a fragmental perspective view of part oi the projectingelements.

Fig. 5 is an enlarged sectional detail taken on iine 5-5 of Fig. 3. v

Fig. 6 is an enlarged perspective View of a portion of the means wherebythe individual slides are centered in the proper display position.

Fig. '7 is an enlarged perspective View of a part of the slide mountingmeans.

Referring in detail to the drawings, and naming rst the principal partsas viewed in Fig. 1, the main casing Ii) has at its front end anupstanding image receiving plate I2, desirably made of a suitablycolored ground glass. vin ornamental border plate I3, which aids informing the front wall of the casing, is shown surrounding said plateI2.

Said casing I is furnished with a floor portion i4 which supports thecasing I5 of a dark chamber I5. Said dark chamber contains, among otherthings, the slide carrier I1 and projector lamp I 8. From the front wallof the casing of the dark chamber extends the tubular lens holder EQcontaining a pair of projection lenses I9a. and Iiib. From said lensesthe image is projected 10 forwardly upon the primary mirror located inthe front part of the casing within a space provided for it below theimage receiving plate I2. From said mirror the image is reflectedbackwardly and at an upward inclination until it encoun- 15 ters therearwardly located secondary mirror 2l. The image is thus progressivelyenlarged and is finally thrown forwardly from the secondary mirror ZI tothe receiving plate I2 upon which it is displayed to the public.

Describing more in detail the construction of the circular slide carrierI'I, said carrier comprises a rotatable table the top of which includesa disc mounted concentrically of the post 24, said disc having a centralopening 25a. to clear 25 the central portion thereof from said post.

Said disc 25 has a series of spaced slide holders 26 mounted inupstanding positions along the peripheral portion thereof. These slideholders are preferably of identical construction, one being 30 shown indetail in Fig. '7. Each includes an angle iron post 2l having a footportion 28 whereby it is secured to disc 25 with its inner angledirected towards the center of said disc. An inner plate it and outerplate 30, both of the same angularity as the post, cooperate with saidpost to form a holder for the adjacent ends of the picture orimageslides 3I. At each side of its lower end the outer angle plate 30has an inwardly directed flange or ear 32 to form a slide support. Said40 angle plates are riveted or otherwise secured to opposite sides ofthe post 2l as shown in Fig. 7, the thickness of the post beingsuiicient to space said angle plates apart sufficiently to provide forready insertion and removal of the end portions of the slides 3l.

The disc 25 has secured to its lower face by screws 25m, a horizontallydisposed gear 34 having a hub portion 34a projecting from its lowerside. Said hub surrounds the post 24 in a spaced rela- 50 tion thereto,but fits rotatably within a tubular bearing member 34e which upstandsfrom and is secured to the floor I4. The weight of the gear is sustainedby an internal` annular iiange 34j of said bearing member 3Ic. The gear34 has an ex- 55 ternal groove 34g surrounding its hub portion and withthis groove cooperates a tension spring 34h under pressure from a screw34k tapped thru the bearing member 34e.

Said gear 34 has teeth 35, said gear being the final gear of a train ofgears which rotates said disc. Said gear 34 is intermittently rotatedone tooth at a time by means of a stud or pin 36 which upstands from ahorizontally ydisposed gear 31, the teeth of which are in mesh wit-h apinion gear 38. Gear 31 is rotatably mounted upon a vertical shaft 39and gear 38 is xed to a live shaft'40. Below pinion gear 38 shaft 40 hasxed to it a gear 4I that is in mesh with the worm gear 42 ixed to theshaft 43 of the motor 44.

In order to prevent over-rotation of the slide carrier I1 when the gearteeth 35 (see Fig. 6) are acted upon by the pin 36 of the gear 31, andalso to position accurately each of the eight slides shown when it comesopposite to the lens holder I9, a control spring 45 is provided. This isa leaf spring having a seat 45s bent thereinto at a point intermediateits end portions to cooperate with the points of gear teeth 35. Saidspring may be arranged to provide a braking surface 45h near its freeend which surface frictionally engages said gear teeth to preventover-rotation. Near its other end said spring is shown secured to abracket 46 to which it is adjustably related in a double manner owing tothe fact that said bracket has a tubular body 41 to receive the turnableand extensible spring supporting pin 48. A set screw 49 holds said pinin the adjusted position. The bracket 46 has a bifurcated foot 50 toprovide for its convenient attachment to any suitable support.Steadiness of rotation is further assured by the tension spring 34h ofFig. 5, which has already been described.

The post 24 is of a tubular character in order that the lamp cord 55 maybe led therethru to supply current to the lelectric lamp I8 alreadymentioned, which is mounted upon the top of said post.V Said post,together with the other vertical shafting which has been mentioned, mayupstand from and be fixed to the floor I4 of the main casing, the floorof the dark chamber I6 being a continuation of the floor of the maincasing.

With the lamp I8 cooperates an assembly of optical elements which isshown surrounded by the operatively mounted plurality of slides 3l andwhich need not be described in detail, as it may be varied to suit theoperator without departing from the spirit of the invention as definedby the claims. It will, therefore, suiice to mention that aconcavo-convex reilector 56 is adjustably mounted at one side of thelamp I8 and a set of three cooperating plano-convex lenses 51, 58, and59 are shown adjustably mounted at the other side of the lamp, all forthe purpose of directing the proper light rays thru whichever of theimage-bearing slides is, at any given time, interposed between the lampand the lenses within the lens holder I9.

The mirrors 20 and 2I will be mounted at the proper inclinations toconvey the image from each picture slide to the proper position on theimage receiving plate I2. It is by the use of these mirrors that theapparatus is adapted to produce a large picture without requiring sogreat an amount of space to do so as has hitherto been deemed necessary.

It will be seen that the diverging rays of light issuing from the lensholder I9 are lengthened out sufficiently to enlarge the image to thedesired extent.

In the operation of the apparatus, owing to the fact that the adjacentteeth 35 of the driven gear have semi-circular notches between them andthese notches are intermittently engaged between eccentric pin 36 withwhich the driving gear is provided, said pin operates in a smooth anduniform manner upon the driven gear reducing strain and wear upon theapparatus.

I claim:

l. In a machine of the kind described, a casing, a source of light,reecting means, a circular slide carrier comprising a disc, a pluralityof polygonally arranged image slides mounted along the peripheralportion of said disc, a gear secured to the lower face of said disc,said gear having a hub portion projecting from the underside thereof andprovided with an external circumferential groove, an upstanding tubularbearing member secured to the floor of said casing, said bearing havingan internal annular flange on which said hub portion is rotatablymounted, a tension spring mounted in a recess in the wall of saidbearing member under pressure to bear upon a face of said groove, saidgear being the nal gear of a train of gearing whereby said carrier isrotated, a driving gear having a driving element eccentrically xedthereto in juxtaposition with said gear, means to mount and rotate saiddriving gear to cause said driving element to engage With a tooth ofsaid gear whereby to advance said carrier to pass said slidessuccessively into display position between said light and said reectingmeans, and an image receiver positioned to receive and display thereflected image.

2. In a machine of the kind described, a casing, a source of light,reflecting means, a circular slide carrier comprising a disc, aplurality of polygonally arranged image slides mounted along theperipheral portion of said disc, a gear secured to the lower faceof saiddisc, said gear having a hub portion projecting from the undersidethereof and provided with an external circumferential groove, anupstanding tubular bearing member secured to the oor of said casing,said bearing having an internal annular flange on which said hub portionis rotatably mounted, a tension spring mounted in a recess in the wallof said bearing member under pressure to bear upon a face of saidgroove, said gear being the final gear of a train of gearing wherebysaid carrier is rotated, a driving gear having a driving elementeccentrically fixed thereto in juxtaposition with said gear, means tomount and rotate said driving gear to cause said driving element toengage with a tooth of said gear whereby to advance said carrier to passsaid slides successively into display position between said light andsaid reflecting means, braking means comprising a spring operativelyrelated to said gear to frictionally contact with the teeth thereof toprevent overrotation of said carrier, and an image receiver positionedto receive and display the reflected image.

3. In a machine Vof the class described, a circular slide carriercomprising a disc, a series of spaced slide holders upstandingly mountedalong the peripheral portion of said disc, said holders comprising anangle iron post having a foot portion whereby it is secured to said discwith the inner angle of the post directed towards the center ofsaid-disc, and an inner plate and an outer plate both of the sameangularity as said post secured to the opposite sides of said post,

said outer plate having at each side of its lower end an inwardlydirected flange to form a slide support for the adjacent ends of thepicture slides when inserted between said plates.

4. In a machine of the class described, a casing, a circular slidecarrier comprising a disc, a series of spaced slide holders upstandinglymounted along the peripheral portion of said disc, said holderscomprising an angle iron post having a foot portion whereby it issecured to said disc with the inner angle of the post directed towardsthe center of said disc, an inner plate and an outer plate both of thesame angularity as said post secured to the opposite sides of said post,said outer plate having at each side of its lower end an inwardlydirected ange to form a slide support for the adjacent ends of thepicture slides when inserted between said plates, a horizontallydisposed gear secured to the lower face of said disc, said gear having ahub portion projecting from its lower side, a tubular bearing member,having an internal annular flange upstandingly mounted on the floor ofsaid casing, said hubportion being rotatably mounted within saidtubular'bearing with the weight of said gear sustained by the internalflange of said bearing member, there being an external groovesurrounding said hub portion, a tension spring cooperating with saidgroove, and a screw tapped thru said bearing member exerting a pressureon said spring.

5. In a machine of the class described, a casing, a circular slidecarrier comprising a disc, a series of spaced slide holders upstandinglymounted along the peripheral portion of said disc, said holderscomprising an angle iron post having a foot portion whereby it issecured to said disc with the inner angle of the post directed towardsthe center of said disc, an inner plate and an outer plate both of thesame angularity as said post secured to the opposite sides of said post,said outer plate having at each side of its lower end an inwardlydirected. flange to form a slide support for the adjacent ends of thepicture slides when inserted between said plates, a horizontallydisposed gear secured to the lower face yof said disc, said gear havinga hub portion projecting from its lower side, a tubular bearing member,having an internal annular flange upstandingly mounted on the iioor ofsaid casing, said hub portion being rotatably mounted within saidtubular bearing with the weight of said gear sustained by the internalflange of said bearing member, there being' an external groovesurrounding said hub portion, a tension spring cooperating with saidgroove, a screw tapped thru said bearing member exerting a pressure onsaid spring, a leaf spring having a seat bent thereinto at a pointintermediate its end portions to cooperate with the points of the teethof said gear and said spring being provided with a braking surface nearits free end to frictionally engage said teeth, and means to mount saidspring in said casing in an operative relation to said gear.

6. In a machine of the class described, a casing, a source of light,reflecting means, a circular slide carrier comprising a disc, a seriesof spaced slide holders upstandingly mounted along the peripheralportion of said disc and comprising an angle iron post having a footportion whereby it is secured to said disc with its inner angle directedtowards the center of said disc, an inner plate and an outer plate bothof the same angularity as said post, means to secure said angle plateswith the opposite sides of said post, said outer angle plate having ateach side of its lower end an inwardly directed flange to form a slidesupport for the adjacent ends of the picture slides, a plurality ofimage slides detachably mounted in said holders, a horizontally disposedgear wheel secured to the lower face of said disc, a wheel, anupstanding pin eccentrically mounted on said wheel, means to mount androtate said wheel to cause said pin to successively contact with theteeth of said gear to intermittently pass said slides successively intodisplay position between said light and said reflecting means, an imagereceiver positioned to receive and display the reflected image, a leafspring having a seat bent thereinto at a point intermediate its endportions to cooperate with the points of said gear teeth and said springbeing provided with a braking surface near its free end to frictionallyengage said teeth to prevent over-rotation of said carrier, means tomount said spring in an operative relation to said gear, said gear wheelhaving a hub portion projecting from its lower side, a tubular bearingmember having an internal annular flange upstandingly mounted on thefloor df said casing, said hub portion being rotatably mounted withinsaid tubular bearing with the weight of said gear sustained by theinternal iiange of said bearing member, there being an external groovesurrounding said hub portion, a tension spring cooperating with saidgroove, and a screw tapped thru said bearing member and exerting apressure on said spring.

'7. In a machine of the kind described, a source of light, reiiectingmeans, a slide carrier comprising a disc having a series of polygonallyspaced slide holders upstandingly mounted along the peripheral portionthereof for detachably securing a plurality of image slides thereto, agear secured to the under side of said disc, the roots of the teeth ofsaid gear being struck with radii whose centers are located in the sameorbit as the path in which said gear rotates whereby the surfaces ofsaid roots are uniformly curved, a driving gear having an eccentricupstanding driving element, means to mount and rotate said driving gearto cause said element in its planetary movement to engage and moveacross the aforesaid curved surfaces of the roots of said teeth one at atime to intermittently drive and thereby rotate said carrier to passsaid slides successively into display position between said light sourceand said reiiecting means in whichever direction said carrier may berotated, means comprising a leaf spring having a seat bent thereinto ata point intermediate its end portions to cooperate with the points ofsaid gear teeth to prevent overrotation, and said spring being providedwith a braking surface near its free end to frictionally engage one ofsaid teeth incident to the seating of another tooth in said seat, and animage-receiver positioned to receive and display the reflected imagewhile the tooth of said gear is so seated.

8. The combination with an intermittently rotated slide carrierincluding a gear whereby it is driven; of a leaf spring operativelyrelated to the tips of the teeth of said gear, said spring having a seatwherein a. tooth of said gear seats during rest periods of said carrier,said spring having its free end portion adapted to graze and effect abraking action on an adjacent tooth.

9. The subject matter of claim 8 and, said braking action occurringprincipally when the rst said tooth approaches and leaves said seat.

FRED BRUNISI-I.

